ABO and infection: Over the past decade, HBGAs have only been considered as co-receptors or co-factors promoting infection in host cells because of the hypotheses that HuNoV genotypes could (i) bind to cells (e.g. lamina propria, Brunner’s gland, and epithelial cells) independently of the presence of HBGAs41,42, (ii) cause acute gastroenteritis outbreaks regardless of the Lewis or ABO phenotypes of secretor individuals43 and (iii) infect non-secretor individuals44,45.